The toxicity and effectiveness of nanoemulsion formulas from Piper retrofractum essential oil against brown plant hopper (Nilaparvata lugens Stål)

Abstract

Secondary metabolite compounds of plants have a role as a self-defence against herbivores and pathogens attacks. The objective of research was to study the toxicity, persistence, and effectiveness of extracts and essential oils of Piper retrofractum against brown plant hopper (BPH). Plant extracts were obtained through maceration method using ethyl acetate solvent for P. retrofractum fruit and essential oils obtained by distillation. Extract toxicity testing uses the contact application method. Polo PC program was used to estimate the LC50 and LC95 value. The results showed that essential oil nanoemulsion from P. retrofractum was the most toxic against BPH nymphs compared to other treatments. The toxicity values from nanoemulsion of essential oils, maceration extracts, and non-nano formula from P. retrofractum extracts 0.19, 0.26, and 0.81 percent respectively. The persistence of the three formulas to BPH nymphs seen starting from one day after the application the average mortality decreased to less than 45 percent. The effectiveness showed that the nanoemulsion from extract and essential oil of P. retrofractum were the most effective use to control BPH nymphs in the green house. The results indicated that extracts and essential oils nanoemulsion of P. retrofractum is the most promising as a botanical insecticide to BPH.